The present disclosure relates generally to systems and methods for imaging a subject and, in particular, to systems and methods for performing computed tomography (CT) imaging without need for rotation capabilities.
Computed tomography is one of the most common diagnostic imaging modality used in modern medicine, enabling rapid, non-invasive image acquisition at high resolution. However, as shown in the example diagram of FIG. 1A, conventional CT systems 10 generally include a gantry 12 fitted with a single X-ray tube 14 (or at most, two X-ray tubes for systems currently in clinical use, not shown) and opposing detector assembly 16, which, together, rotate about a subject 18 to acquire multiple projections for reconstructing an image. That is, the X-ray tube 14 and detector assembly 16 arranged opposite the X-ray tube 14 are affixed to the gantry 12 and rotate together with the gantry 12 about the subject 18. As illustrated in the picture of FIG. 1B, this architecture is complex and requires heavy and sophisticated control hardware and electronics, which increases the cost and limits availability in developing countries, or in resource-limiting environments, such as a battlefield. In addition, the temporal resolution attained using conventional CT systems is also limited by the time required for the gantry to mechanically complete a significant portion of an angular rotation. As a result, the reduced temporal resolution amplifies motion artifacts due to breathing or involuntary motion of a patient, affecting the spatial resolution achievable and degrading the quality of the reconstructed image.
In attempts to overcome such limitations, introduced “fifth generation” CT designs have avoided use of a rotating gantry in lieu of stationary components. In particular, such CT systems include a fixed electron emitter along with elements for directing a generated electron beam to multiple anode strips partially occupying a gantry encircling the patient. Generated. X-ray beams traversing the patient are then detected by a detector array occupying the remainder of the gantry. Although capable of fast scanning, such CT systems require steering of energetic electron beams along the circumference of gantry, suffer from limited photon flux, and may not cover a full 360 degree angle perspective of the patient. In addition to a large system footprint, fifth generation CT scanners are also associated with high costs and are difficult to calibrate, thus limiting their practical application. Furthermore, in existing stationary and non-stationary CT system designs, a small failure in one of the components renders the entire system to be inoperable.
Therefore, given the above, there is a need for systems capable of fast and accurate computed tomography imaging that is not so limited by complexity and size.